Definición de grand mal en inglés:

sustantivo

Epilepsy is called grand mal (major illness) or petit mal also called absence attacks.

In this kind of epilepsy, also known as grand mal epilepsy, nerve cells in both sides of the brain become overactive at the same time. Seizures usually last for about five minutes, and can be alarming.

He reassured her that she would not develop the type of epilepsy called grand mal in which people lose conscious-ness.